The atmosphere on this isolated stretch of the Suffolk coast is almost impossible to describe. The vast skies and pewter clouds are strafed with mercurial winter sunshine.

The rare, vegetated shingle beach rolls desert and lunar landscape into one, while the sentinel presence of four Napoleonic Martello towers suggest there is more to this inscrutable place than meets the eye.

In May 1940, when a German invasion was thought to be imminent, the civilian population of Shingle Street was evacuated and minefields laid on the beach.

And it was then that the rumours began: that a small German invasion force had landed at Shingle Street, a battle had broken out as defenders beat the invaders back to the water, and that the Germans had been burned alive with oil and petrol pumped on to the surface of the sea using special pipelines.

Rumours of German invasion were rife along the south and east coast in the war, but such was the pitch of speculation on this incident that it led to questions in the House of Commons and, in 1993, the early release of classified documents. These revealed the ‘invasion’ was just a rumour – although the bodies of four dead German airmen had washed up on the beach, after their plane crashed into the North Sea.

These days, as you walk along the beach with its mirror-surfaced lagoons and overgrown pillboxes that are more plant than brick, the sense of a place steeped in mystery remains.